The present invention relates to an improved short-range practice round for simulating a kinetic energy type armor-piercing ammunition round, which includes an armor-piercing subprojectile mounted in a full-caliber discarding sabot and is fired from tank or other cannon at high velocities.
U.S. Pat. No. 4,140,061 discloses a practice round of the aforesaid type, which contains a self-destruct subprojectile composed of a plurality of contiguous elongated mating segments held together by a heat sensitive nose cap of metal. During flight the metal nose cap is heated aerodynamically, causing it to burn and disintegrate and thereby release the segments to tumble and decelerate and come to rest at a predetermined range. The nose cap recently employed was fabricated of a zinc alloy. However, the metal nose cap design is not completely satisfactory, since the disintegration thereof is progressive and relatively slow, so that it is difficult to achieve the exact time and range when the subprojectile aborts. The difficulty is further compounded by other factors which can influence the rate of heating of the nose cap, e.g. configuration and composition of the metal nose cap, projectile velocity, atmospheric temperature, etc.